Pacific mackerel (Scomber japonicus) stock assessment for USA management in the 2015-16 and 2016-17 fishing years P. R. Crone and K. T. Hill NOAA/SWFSC/FRD 8901 La Jolla Shores Dr. La Jolla, CA 92037, USA Agenda Item G.2.a Supplemental Stock Assessment PowerPoint (Electronic Only) June 2015
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Pacific mackerel (Scomber japonicus) stock assessment for USA management
in the 2015-16 and 2016-17 fishing years
P. R. Crone and K. T. HillNOAA/SWFSC/FRD8901 La Jolla Shores Dr.La Jolla, CA 92037, USA
Candidate models (A-G, H1b, H3) (see Table 5, p. 54)P. mackerel stock assessment (2015)
Model H3 – STAT’s selected model
• Reflects an updated configuration that includes similar data and parameterizations as last accepted model for advising management
• Plausible configuration with reasonable fits to input time series
• Robust in most diagnostic investigations
• Results consistent with external information regarding stock size/availability, e.g., AT survey abundance index, unrealized quotas in USA, limited catches in Mexico
• Bottom-line results useful to management similar to model that included AT survey data
P. mackerel stock assessment (2015)
Model H3 – Fits to mean length-at-age dataP. mackerel stock assessment (2015)
CA comm. fishery age composition CPFV length composition
P. mackerel stock assessment (2015) – Model H3
Model H3 – Selectivity
P. mackerel stock assessment (2015) - Results
Model H3 – Fit to CPFV index of relative abundance
• AT surveyo Long-term support needed for monitoring small pelagic species assemblageo Expand survey area (address stock distribution assumptions)o Improve trawl sampling operations
• Model developmento Develop a prior and plausible bounds for catchability coefficient (q)o Population scale (selectivity/robustness) Selectivity: dome-shaped vs. asymptotic (fishery age compositions) Age data from all fisheries/survey; more flexible selectivity forms, time-varying
processes, data weighting schemes
• International relationso Survey collaboration, improve fishery data exchange
• Fishery/survey biological samplingo Pacific NW size/age data, AT survey age data, Mexico size/age datao Coordinated production ageing programs